Modelle des Kosmos: Modelle des Himmels
The Michael Sendter precision engineering factory received the contract to build the Ptolemaic and Copernicanist planetarium. Both of the planetaria have a special mechanism for moving the celestial stars according to the relevant system, and can be set in motion by a crank.
The mechanisms of both planetaria differ according to the systems they represent. For the Ptolemaic planetarium, the crank moves the celestial bodies rotating around the earth, while the glass globe simultaneously moves with the stars of the fixed sky using a sprocket.